Installation for venting the cooling liquid of an internal compustionengine

ABSTRACT

An installation for venting the cooling liquid of an internal combustion engine by means of an expansion tank, in which the expansion tank is interconnected into an auxiliary circulation of the cooling liquid and the auxiliary circulation is connected in parallel to the main circulation, and in which at least one geodetic high-point of the main circulation is connected to its own universal vent line and the universal vent line terminates in the interior space of the expansion tank; the expansion tank is thereby adapted to be selectively connected with the atmosphere or closed off with respect thereto while a one way check-valve precluding the flow from the expansion tank to the geodetic highpoint is connected in effect between the high-point of the universal vent line and the interior space of the expansion tank.

United States Patent Pabst June 28, 1974 1 INSTALLATION FOR VENTING THE COOLING LIQUID OF AN INTERNAL COMBUSTION ENGINE [75] Inventor: Rolf Pabst, Neuhausen, Germany [73] Assignee: Daimler-Benz Aktiengesellschaft 221 Filed: Nov. 30, 1971 [2]] Appl. No.: 203,372

[30] Foreign Application Priority Data 'Ferguson l65/l 10 3/1970 Aurea 9/ l 971 123/4154 Morse et al l23/4l.54 X

[57] ABSTRACT An installation for venting the cooling liquid of an internal combustion engine by means of an expansion tank, in which the expansion tank is interconnected into an auxiliary circulation of the cooling liquid and the auxiliary circulation is connected in parallel to the main circulation, and in which at least one geodetic high-point of the main circulation is connected to its own universal vent line'and the universal vent line terminates in the interiorspace of the expansion tank; the expansion tank is thereby adapted to be selectively connected with the atmosphere or closed off with respect thereto while a one way check-valve precluding the flow from the expansion tank to the geodetic highpoint is connected in effect between the high-point of the universal vent line and the interior space of the expansion tank.

12 Claims, 2 Drawing Figures INSTALLATION FOR VENTING THE COOLING LIQUID OF AN INTERNAL COMBUSTION ENGINE The present invention relates to an installation for venting the cooling liquid of an internal combustion engine by means of an expansion tank, in which the expansion tank is connected into an auxiliary circulatory system of the cooling liquid and the auxiliary circulatory system is connected in parallel to the main circulatory system of the cooling liquid enforced by a pump, and in which at least one geodetic high-point of the main circulatory system is connected to its own universal vent line for the operating and filling venting and in which the universal vent line terminates in the interior space of the expansion tank and can be selectively connected with the atmosphere or closed off with respect to the latter.

An installation of this type has been already proposed heretofore and offers the advantage that the high-point of the universal vent line can be located geodetically higher than the auxiliary circulatory system and/or the internal combustion engine. As a result thereof, for example, the geodetic location of the radiator in motor vehicles thereby becomes independent from the arrangement of the driving engine.

The present invention represents a further development of the prior proposal and essentially consists in that a one-way check-valve preventing the flow from the expansion tank to the high-point is effectively connected between the high-point of the universal vent line and the interior space of the expansion tank.

-It is made possible by the further development according to the present invention that the high-point of the. universal vent line can be located in the section between the thermostat valve and the pump of the main circulatory system, without the existence of the danger that a cooling flow by-passing the thermostat valve can occur in the universal vent line from the expansion tank tothe pump. An advantageous arrangement of the one-way checkvalve in connection with a simple construction of the means for the selective connection or closing of the universal vent line in relation to the atmosphere is achieved as a further feature and development of the installation according to the present invention in that the universal vent line terminates in a chamber of the filling pipe which is closed off with respect to the atmosphere by the filling pipe closure means and with respect to the interior space of the expansion tank by the one-way check-valve.

Accordingly, it is an object of the present invention to provide an installation for the venting of the cooling liquid of an internal combustion engine which effectively prevents by simple means the aforementioned shortcomings and drawbacks encountered in the prior art. 1

Another object of the present invention resides in an installation for venting the cooling liquid of an internal combustion engine which permits greater freedom in the design and layout of the system without danger of a bypass flow from the expansion tank to the pump in the universal vent line.

A further object of the present invention resides in an installation for venting the cooling liquid of an internal combustion engine which is simple in construction, re-

liable in operation and utilizes relatively few and inexpensive parts.

These and further objects, features, and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIG. 1 is a schematic view of the overall cooling liquid system of a motor vehicle in accordance with the present invention, and

FIG. 2 is a partial cross-sectional view, on an enlarged scale, illustrating the detail X, encircled in dash and dot lines in FIG. 1.

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate like parts, the flow-line for the cooling liquid leading from the cylinder head 10 of the engine 11 to the radiator 12 is designated inFIG. l by reference numeral 13. The return line of the cooling liquid leading from the radiator 12 to the circulating pump 14 driven by the engine 11 is designated by reference numeral 15.

The circulating pump 14 supplies the cooling liquid by way of a pressure line 16 to the cooling spaces of the cylinders, from which are fed the cooling spaces of the cylinder head 10.

The operating temperature of the cooling liquid in the engine is adjusted in the usual manner to an average value by a thermostat valve 17 interconnected into the flow-line 13, whereby the valve 17 controls the flow in the radiator 12 as well as in a bypass line 18 which connects the flow-line 13 with the suction connection 19 of the pump 14 in bypassing'the radiator 12.

The main circulatory system of the cooling liquid is constituted by the lines l3, 15, 16 and 18 whereas an expansion tank generally designated by reference numeral 20 for the volume equalization of the cooling liquid is interconnected in an auxiliary circulatory system for the cooling liquid which is constituted by an operating vent line 21 as well as a filling line 22. The operating vent line 21 is branched off from the flow-line 13 between the cylinder head 10 and the thermostat valve 17 and terminates at a place generally designated by reference numeral 23 below the lowest permissive liquid level in the expansion tank 20. The filling line 22 connects the discharge opening 24 of the expansion tank 20 with the suction connection 19 of circulating pump 14.

Into the upper portion of the expansion tank 20 is inserted in a pressure-tight manner a filler pipe 25 which includes at the upper end an upper filling chamber 26 (FIG. 2).'The filling chamber 26 is closed off with respect to the atmosphere by the threaded closure means 27 of the filling pipe stub and with respect to the interior space of the lower collecting chamber 28 of the expansion tank 20 by a valve mechanism generally designated by reference numeral 29. A universal vent line 30 terminates in the filling chamber 26, which is connected at its other end with the upper water box 31 of the radiator 12. During the filling of cooling liquid the screw cap 27 is removed so that in this case the universal vent line 30 for the filling ventilation of the water box 31 forming a high-point of the main circulation is in communication with the atmosphere. After the closure of the filling pipe 25 by means of the screw cap 27, the one-way closure or check-valve 32 of the valve mechanism 29 is connected between the universal vent line 30 and the interior space 28 of the expansion tank 20 so that the flow from the collecting chamber 28 to the water box 31 is blocked and is released in the opposite direction after overcoming a slight spring-stress for the operational venting of the water box 31. By this arrangement the thermostat valve 17 is ineffectual since the universal vent line 30 forms a bypass with respect to the valve 17.

The valve mechanism 29 may consist of a valve seat plate 33 which is adhesively connected with an annular seal 34. The annular seal 34 is pressed by a compression spring 35 inserted between the screw cap 27 and the valve seating plate 33 against an annular bead 36 of the filler pipe 25 forming a valve ring seat. A valve spring 37 is further supported at the valve seat plate 33, which forces the one-way check-valve 32 against the ring seal 34.

The valve mechanism 29 and the screw cap member 27 may form a structural unit adapted to be preassembled.

OPERATION To fill the system with cooling water with engine turned off, the filler cap 27 and the valve seat plate 34 are removed together with the one-way valve 32. Since the thermostat valve 17 is closed the flow line 13 is connected with bypass line 18. During the filling operation, the cooling water flows via filling line 22 on the one hand into the cylinder head of the engine 11 through circulating pump 14 and pressure line 16 and, on the other hand, via return line into the radiator 12. The air enclosed or trapped in return line 15 and radiator 12 escapes into the atmosphere via universal vent line 30 and chamber 26, whereas the air being enclosed or trapped in the cylinder head 10 of the engine 11 is collected in operating vent line 21.

Upon starting the engine 11 with the thermostat valve 17, cap 27 and one-way valve 32 closed, pump 14 suctions in cooling water via filling line 22 and by-pass line 18 and forces it into the cylinder head 10 of the engine 11. A partial quantity from flow line 13 of cooling water and enclosed or trapped air flows via operating vent line 21 into expansion tank where the air is separated, or led off into the interior space 28. The oneway valve 32 prevents the pump 14 from suctioning in air from the interior space 28 via universal vent line 30, radiator 12 and return line 15.

During operation of the engine with thermostat valve 17 either completely or partially open, cooling water flows from flow line 13 via thermostat valve 17 into radiator 12 and return line 15 toward circulating pump 16.

While we have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art, and we, therefore, do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What I claim is:

1. An installation for venting the cooling liquid of an internal combustion engine comprising: an expansion tank means including a filling chamber and a lower collecting chamber, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, said auxiliary circulatory system including a first vent line means connected to a first point in said main circulatory system and to the interior space of said lower collecting chamber and a filling vent line means connected to a further point in said main circulatory system and to the interior space of said collecting chamber for conveying the cooling liquid from the interior space of said collecting chamber to said main circulatory system. a third vent line means having one end connected to at least one geodetic high-point of said main circulatory system for the operational filling and venting, the other end ofsaid third vent line means terminating in the interior space of said filling chamber, means for selectively sealing said filling chamber from the atmosphere, and venting means for establishing a venting connection between said filling chamber and said lower collecting chamber for operation venting and filling venting, said venting means including a one-way check-valve means opening into said collecting chamber for the operating venting process and additional means for selectively sealing said filling chamber from said lower collecting chamber for the filling venting process.

2. An installation according to claim 1, including a radiator having an upper water box wherein said geodetic high-point is formed by said upper water box.

3. An installation according to claim 1, wherein said one-way valve is disposed in an opening provided between of said filling chamber and said lower collecting chamber, and wherein said additional sealing means includes a loosely disposed valve seat plate means for selectively covering said opening, edge means on said opening means for sealingly engaging said valve seat plate means, means for biasing said valve seat plate means into engagement with said edge means, said means for biasing being disposed between said valve seat plate means and said means for selectively sealing said filling chamber.

4. An installation according to claim 1, further including means connecting said sealing means for said filling chamber and said additional sealing means to substantially simultaneously release said sealing means and said additional sealing means.

5. An installation for venting a cooling liquid of an internal combustion engine comprising: an expansion tank means, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, a universal vent line means connected to at least one geodetic high-point of said main circulatory system for the operational and filling venting, said universal vent line means terminating in a chamber of a filler pipe disposed in the interior space of said expansion tank, a filler pipe closure means for selectively connecting or closing off said expansion tank means with respect to the atmosphere, and a one-way check valve means for preventing the flow from said expansion tank means to said geodetic high-point connected effectively between a high-point of said universal vent line means and the interior space of said expansion tank means by closing off said filler pipe chamber from said interior space of said expansion tank means.

6. An installation according to claim 5, including a radiator having at least an upper water box, wherein said geodetic high-point of the main circulatory system is formed by said upper water box.

9. An installation according to claim 8, including a thermostat valve wherein an operational vent line is provided having one end thereof connected at a point in the main circulatory system between the engine and said thermostat valve and the other end thereof terminating in said expansion tank means at a point below the lowest permissive cooling liquid level.

10. An installation according to claim 9, including a radiator and a by-pass line wherein said main circulatory system includes a pump connected between said radiator and said bypass line, and a line connecting said expansion tank means with said main circulatory system between said pump and outlet of said radiator.

1 1. An installation for venting the cooling liquid of an internal combustion engine comprising: an expansion tank means, a main circulatory system of thecooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, a first vent line means connected to at least one geodetic highpoint of said main circulatory system for operational filling and venting, said first vent line means terminating in the interior space of said expansion tank means, said auxiliary circulatory system including a second vent line means connected to another point in said main circulatory system and to the interior space of said expansion tank means for conveying at least a portion of the cooling liquid to said expansion tank means, filling vent line means connected to a further point in said main circulatory system and to the interior space of said expansion tank means for conveying the cooling liquid from the interior space of said expansion tank means to said main circulatory system, means for selectively connecting or closing off said expansion tank means with the atmosphere, a one way check-valve means disposed in the interior space of said expansion tank means for preventing the flow through said first vent line means from said expansion tank means to said geodetic high-points of said main circulatory system, and a thermostat valve provided in said main circulatory system, said second vent line means being an operational vent line having one end thereof connected at a point in the main circulatory system between the engine and said thermostat valve and the other end thereof terminating in said expansion tank means at a point below the lowest permissive cooling liquid level.

12. An installation for venting the cooling liquid of an internal combustion engine comprising: an expansion tank means, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, a first vent line means connected to at least one geodetic highpoint of said main circulatory system for the operational and filling venting, said first vent line means terminating in the interior space of said expansion tank means, said auxiliary circulatory system including a second vent line means connected to another point in said main circulatory system and to the interior space of said expansion tank means for conveying at least a portion of the cooling liquid to said expansion tank means, a filling vent line means connected to a further point in said main circulatory system and to the interior space of said expansion tank means for conveying the cooling liquid from the interior space of said expansion tank means to said main circulatory system, means for selectively connecting or closing off said expansion tank means with the atmosphere, a one-way checkvalve means disposed in the interior space of said expansion tank means for preventing the flow through said first vent line means from said expansion tank means to said geodetic high-points of said main circulatory system, a radiator, and a by-pass line, said main circulatory system including a pump connected between said radiator and said by-pass line, said third vent line means being connected with said main circulatory system between said pump and the outlet of said radia- 

1. An installation for venting the cooling liquid of an internal combustion engine comprising: an expansion tank means including a filling chamber and a lower collecting chamber, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, said auxiliary circulatory system including a first vent line means connected to a first point in said main circulatory system and to the interior space of said lower collecting chamber and a filling vent line means connected to a further point in said main circulatory system and to the interior space of said collecting chamber for conveying the cooling liquid from the interior space of said collecting chamber to said main circulatory system, a third vent line means havIng one end connected to at least one geodetic high-point of said main circulatory system for the operational filling and venting, the other end of said third vent line means terminating in the interior space of said filling chamber, means for selectively sealing said filling chamber from the atmosphere, and venting means for establishing a venting connection between said filling chamber and said lower collecting chamber for operation venting and filling venting, said venting means including a one-way check-valve means opening into said collecting chamber for the operating venting process and additional means for selectively sealing said filling chamber from said lower collecting chamber for the filling venting process.
 2. An installation according to claim 1, including a radiator having an upper water box wherein said geodetic high-point is formed by said upper water box.
 3. An installation according to claim 1, wherein said one-way valve is disposed in an opening provided between of said filling chamber and said lower collecting chamber, and wherein said additional sealing means includes a loosely disposed valve seat plate means for selectively covering said opening, edge means on said opening means for sealingly engaging said valve seat plate means, means for biasing said valve seat plate means into engagement with said edge means, said means for biasing being disposed between said valve seat plate means and said means for selectively sealing said filling chamber.
 4. An installation according to claim 1, further including means connecting said sealing means for said filling chamber and said additional sealing means to substantially simultaneously release said sealing means and said additional sealing means.
 5. An installation for venting a cooling liquid of an internal combustion engine comprising: an expansion tank means, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, a universal vent line means connected to at least one geodetic high-point of said main circulatory system for the operational and filling venting, said universal vent line means terminating in a chamber of a filler pipe disposed in the interior space of said expansion tank, a filler pipe closure means for selectively connecting or closing off said expansion tank means with respect to the atmosphere, and a one-way check valve means for preventing the flow from said expansion tank means to said geodetic high-point connected effectively between a high-point of said universal vent line means and the interior space of said expansion tank means by closing off said filler pipe chamber from said interior space of said expansion tank means.
 6. An installation according to claim 5, including a radiator having at least an upper water box, wherein said geodetic high-point of the main circulatory system is formed by said upper water box.
 7. An installation according to claim 5, wherein said one-way check-valve means includes a spring-loaded valve plate provided with an annular seal pressed against a valve ring seat formed by the filler pipe closure means.
 8. An installation according to claim 7, wherein said one-way check-valve is operable to selectively open and close an aperture in said spring-loaded valve plate.
 9. An installation according to claim 8, including a thermostat valve wherein an operational vent line is provided having one end thereof connected at a point in the main circulatory system between the engine and said thermostat valve and the other end thereof terminating in said expansion tank means at a point below the lowest permissive cooling liquid level.
 10. An installation according to claim 9, including a radiator and a by-pass line wherein said main circulatory system includes a pump connected between said radiator and said bypass line, and a line connecting said expansion tank means with said main circulatory system between saId pump and outlet of said radiator.
 11. An installation for venting the cooling liquid of an internal combustion engine comprising: an expansion tank means, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, a first vent line means connected to at least one geodetic high-point of said main circulatory system for operational filling and venting, said first vent line means terminating in the interior space of said expansion tank means, said auxiliary circulatory system including a second vent line means connected to another point in said main circulatory system and to the interior space of said expansion tank means for conveying at least a portion of the cooling liquid to said expansion tank means, filling vent line means connected to a further point in said main circulatory system and to the interior space of said expansion tank means for conveying the cooling liquid from the interior space of said expansion tank means to said main circulatory system, means for selectively connecting or closing off said expansion tank means with the atmosphere, a one way check-valve means disposed in the interior space of said expansion tank means for preventing the flow through said first vent line means from said expansion tank means to said geodetic high-points of said main circulatory system, and a thermostat valve provided in said main circulatory system, said second vent line means being an operational vent line having one end thereof connected at a point in the main circulatory system between the engine and said thermostat valve and the other end thereof terminating in said expansion tank means at a point below the lowest permissive cooling liquid level.
 12. An installation for venting the cooling liquid of an internal combustion engine comprising: an expansion tank means, a main circulatory system of the cooling liquid, an auxiliary circulatory system of the cooling liquid connected in parallel to said main circulatory system and to said expansion tank means, a first vent line means connected to at least one geodetic high-point of said main circulatory system for the operational and filling venting, said first vent line means terminating in the interior space of said expansion tank means, said auxiliary circulatory system including a second vent line means connected to another point in said main circulatory system and to the interior space of said expansion tank means for conveying at least a portion of the cooling liquid to said expansion tank means, a filling vent line means connected to a further point in said main circulatory system and to the interior space of said expansion tank means for conveying the cooling liquid from the interior space of said expansion tank means to said main circulatory system, means for selectively connecting or closing off said expansion tank means with the atmosphere, a one-way check-valve means disposed in the interior space of said expansion tank means for preventing the flow through said first vent line means from said expansion tank means to said geodetic high-points of said main circulatory system, a radiator, and a by-pass line, said main circulatory system including a pump connected between said radiator and said by-pass line, said third vent line means being connected with said main circulatory system between said pump and the outlet of said radiator. 